How get lat and long of a point?

Question

I am new for iPhone developer. I am designing a project in which i have given starting and ending point address. Suppose i get distance between those points is 100 miles and i divide in five equal parts of 20 miles. Then how get lat and long of point far 20 miles from starting point?

Answer 1

Add this function to your class:

// position is a number between 0 and 1, where 0 gives the start position, and 1 gives the end position
- (CLLocationCoordinate2D)pointBetweenStartPoint:(CLLocationCoordinate2D)startPoint endPoint:(CLLocationCoordinate2D)endPoint position:(float)position {

    CLLocationDegrees latSpan = endPoint.latitude - startPoint.latitude;
    CLLocationDegrees longSpan = endPoint.longitude - startPoint.longitude;

    CLLocationCoordinate2D ret = CLLocationCoordinate2DMake(startPoint.latitude + latSpan*position,
                                                            startPoint.longitude + longSpan*position);

    return ret;
}

You can then use this method like this (assuming you want to split the distance into 5):

CLLocationCoordinate2D startPoint = CLLocationCoordinate2DMake(/* lat, long of start point */);
CLLocationCoordinate2D endPoint = CLLocationCoordinate2DMake(/* lat, long of end point */);

for (int i = 1; i < 5; i++) {
    float position = i / 5.0;
    CLLocationCoordinate2D middlePosition = [self pointBetweenStartPoint:startPoint endPoint:endPoint position:position];
    NSLog("%f, %f", middlePosition.latitude, middlePosition.longitude);
}